The present invention pertains generally to the field of archiving digital data and more specifically to compressed archives.
Many business enterprises generate large amounts of electronic data that are archived for a variety of purposes. Examples include archiving transaction data for auditing, customer service or data mining uses. A business enterprise may also be required to archive electronic data for regulatory purposes.
The life cycle of most enterprise data begins with generation of the data during some sort of customer interaction or transaction. The enterprise data is typically created and initially stored within a database system. The advantage of a database system is that the data is organized into data structures that may be rapidly queried. However, most database systems impose some limitations on the amount of data that is stored. Some database systems simply have a finite limit on the amount of data that may be accessed. Other database systems may be able to accommodate large amounts of data but may be expensive to maintain when the database system exceeds a certain size. Therefore, database systems are not typically used to archive large amounts of data for long periods of time.
One method used to archive large amounts of data is to store the data on serially accessed file systems such as a tape system or on a randomly accessed file system such as a large or distributed disc drive system. Tape system storage is inexpensive; however, it is cumbersome in that the data must be reloaded into a database system before the data can be queried. Disc storage systems are more expensive than tape systems but offer greater accessibility. However, if the data is stored as conventional files, the data must still be loaded into a database system before the data can be accessed or queried.
As large database systems are an expensive solution to archiving data and conventional file storage systems do not lend themselves to convenient access, it would be desirable to have an archive system that is both easy to query and inexpensive to maintain.